US 6782721 B1
A method of producing a unilayer textile fabric having in preselected areas fibers of a heavier denier inserted pursuant to a computer program and the articles produced thereby. There is also provided a glove prepared by the method comprising heavier denier fibers at preselected locations.
1. A unilayer flexible textile performance fabric comprising a chain stitched base fabric having a design of a pattern formed therein by the continuous step of selectively manipulating and chain stitching into said fabric at least one insertion fiber of a higher denier into said base fabric with a single knitting needle wherein said step of manipulating is computer controlled to form a unilayer.
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14. A single layer protective fabric comprising a base fabric formed by chain-stitching a first fiber of a lighter denier, said base fabric having a design of a pattern formed therein by the step of manipulating and chain stitching into said base fabric with a single knitting needle at least one insertion fiber of a heavier denier, wherein said step of manipulating is controlled by an output signaling a programmed microprocessor so as to form at least one island of high denier fiber.
15. A method of manufacturing a unilayer flexible insertion fabric comprising the steps of:
(a) manipulating and chain stitching a first fiber of a higher denier to form a base textile fabric in a unilayer; and
(b) manipulating and chain stitching at least one insertion fiber of heavier denier into said base fabric with a single knitting needle to form a unilayer, wherein the step of manipulating is computer controlled to produce a predetermined design for pattern to form a performance fabric having enhanced performance functions.
16. The method according to
17. The method according to
This application is a continuation-in-part of application Ser. No. 10/060,718, filed Jan. 30, 2002.
The present invention relates generally textile fibers with selectively placed interlocking of an insertion fiber of a heavier denier to produce garments and articles having enhanced performance characteristics. More particularly, the invention relates to protective work garments. The invention also relates to a method of producing a unilayer textile fabric where the insertion fibers are knitted into pre-selected locations within the base textile fabric and the process is controlled by a computer.
The prior art has provided fabric of specific constructive design to overcome particular hazards encountered in the work environment. Generally in such construction, the patents disclose composite requiring layers of high tensile modular filaments which may be further treated by dipping to form a protective fiber or by heat treatment. Such is the case in providing cut resistant fabric for gloves for use by metal working, glass handlers, meat cutters, and medical personnel. Each requires protection from a different hazard. The metal workers and glass handlers typically do not need protection from fluids. On the other hand, meat cutters and medical personnel do need this fluid protection to prevent bacterial or viral infection.
U.S. Pat. No. 4,004,295 discloses a glove constructed of yarn and metal wire and a non-metallic fiber such as an aramide fiber as protection from knife cuts.
U.S. Pat. No. 4,651,514 relates to a yard composed of a monofilament nylon core that is wrapped with at least one strand of aramide fiber and a strand of nylon fiber. This yarn is electronically nonconductive.
Other special fabrics are designed for firefighters, foundry workers, and personnel in the chemical and related industries. Again, additional protection beyond the cut and puncture resistance is required. Generally, this again involves protecting the skin from hazardous liquid chemicals. These include solvents, paints, varnishes, glues, cleaning agents, degreasing agents, drilling fluids, inter alia.
U.S. Pat. Nos. 4,479,368 and 4,608,642, which are herein incorporated by reference disclose programmable knitting machines which may be used in preparing the fabrics of the invention.
U.S. Pat. No. 4,302,851 to Adair discloses a heat resistant protective hand covering in which a wool knit liner is enclosed within an outer layer of woven KEVLAR® aromatic polyamides fiber material with layers of aluminum foil and flexible fiberglass sandwiched there between a pleated pad of flexible material woven from fiberglass yarns.
U.S. Pat. No. 4,433,479 to Sidman et al, relates to a heat resistant glove having first and second shells formed of temperature-resistant aromatic polyamide fibers such as KEVLAR® with the first shell section being made of a twill weave fabric and the second shell being made of a knitted fabric. A liner is formed of two sections, both are made of a felt fabric of temperature resistant aromatic polyamide fibers with the section forming the palm being provided with a flame resistant elastomeric coating.
U.S. Pat. No. 5,965,223 to Andrews et al, which is herein incorporated by reference discloses a composite layer protective fabric having an outer primary layer of an abrasive material and an inner layer of a cut resistant material positioned below the outer layer.
In each case the prior art discussed above requires a plurality of layers to achieve the protection desired. Usually each layer being fabricated of a uniform composite structure. Thus the weight of the fabric is increased and the flexibility and comfort level of the wearer of the garment produced is decreased. Furthermore, the extensive use of high performance filaments makes the articles of manufacture more expensive.
Therefore, there exists a need for a flexible and comfortable textile performance fabric that is less expensive, more efficient to fabricate, and reduces the amount of high performance filaments yet provides the necessary protective characteristics.
In accordance with the present invention a flexible unilayer textile fabric is produced in which the interlocking or intertwining of at least one insertion fiber into pre-selected patterns at definite locations or regions of a base fabric by essentially conventional textile manipulating techniques controlled by a computer. The base fabric is formed from natural material or synthetic polymer fibers of a lighter mass or lower denier than the insertion fiber. The “insertion fiber” may be of the same or different material than the base fabric but of a heavier denier. The insertion fibers may include performance filaments which can be used and have a high tensile modulus of elasticity of about 5,000 kg/mm2 or more. The high tensile modulus filaments used may vary widely and include organic and inorganic filaments depending on the functional use. However, these high performance materials are very expensive and reducing the amounts without sacrificing performance is accomplished by the present invention.
For comfort and economic reasons the base fabric is manufactured preferably from a lighter and less expensive natural fiber such as cotton. As mentioned above, the type of high tensile modulus filament to be used is predicated on improving the effectiveness of the fabric for an intended function. For example, if garments are expected to provide protection to the wearer from hazards such as abrasions, cuts, and punctures, a cut resistant filament is knittingly secured into the base fabric by a computer controlled pattern device. The encoded pattern information (design and location data) will direct the manipulation of the needles to interlock the filaments. In the case of a garment such as a glove, all regions where such reinforcement is needed, which could include shoulder length glove, the present invention can be used. Preferably the interlocking step is done by knitting. The high tensile modulus filaments are selected from the group consisting of aramides, extended chain polyethylenes, extended chain polypropylenes, liquid crystal polyesters, polyolefins, polyesters, polyamides, carbon fibers, metal fibers, fiberglass, and mixtures thereof.
The invention provides a method of manufacturing a unilayer flexible performance textile fabric having an insertion fiber of a heavier denier interlocked or intertwined within the base fabric to enhance an intended function. The first step involves manipulating the lower denier fiber using substantially conventional textile fabric forming technology such as stitching to form a basic fabric. The next step also follows conventional techniques such as by knitting the heavier denier insertion fiber base fabric wherein the placement and design of the pattern of the heavier denier fiber is controlled by the pattern data supplied to a microprocessor to which the manipulations of the knitting needles are responsive providing the pattern programmed in the same single layer as the base fabric.
It is the primary objective of the invention to provide a unilayer fabric that enhances the performance of an intended function, yet reduces the weight of the apparel or article of manufacture with single layer construction.
Another object of the invention is to provide a fabric containing high tensile modulus filaments of a heavier denier in pre-selected locations within the fabric.
A further object of the invention is to provide a large variety of apparel and articles fabricated from the fabric of the invention.
A still further object of the present invention is to provide performance apparel used for protection against numerous potential hazards.
Yet another object of the present invention is to maximize the effectiveness of expensive high performance material.
Still another object of the present invention relates to articles of manufacture fabricated totally or in part of a glove from fabric of this invention.
Another object of the present invention is to provide a glove construction of a unilayer fabric with high tensile modular filaments of a heavier denier than the base fabric and knitted into the base fabric conforming to the pattern and location programmed and controlled by a computer to form “islands of reinforcement” in the finger, thumb, and palm, heel wrist, and arm regions against sharp objects.
FIG. 1A is a glove formed by the method of the invention;
FIG. 1B is a sectional view, taken generally along line 1B—1B in FIG. 1A showing the unilayer construction of the thumb stall;
FIG. 2A shows a prior art method of chain looping two different fibers together in a single layer;
FIG. 2B illustrates the prior art double layer method of chain linking two different fibers;
FIG. 3 shows a flow diagram of the process of the invention.
As shown in FIG. 1A there is provided a fabric in the form of a knit glove 10 with an elastic band 13 and having a substantial area of cotton and two areas of a heavier denier with a high modulus synthetic fiber 12 such as KEVLAR®. Both the cotton fibers 11 and the synthetic fibers are single layered. Optionally the synthetic fiber can be replaced with a larger denier cotton fiber. The prior art method to provide a reinforcement has generally been to overknit an area so as to form a double layer.
FIG. 2A illustrates a prior art method of incorporating a high modulus fiber 14 to form a single layer fabric by primarily alternating the looping of a synthetic fiber onto a natural fiber 15.
FIG. 2B illustrates the prior art method of forming fabrics with a layer of a double layer natural fiber 15 that is looped with a high modulus fiber 14.
FIG. 3 shows a flow diagram of the composite controlled process used in the process wherein a microprocessor 20 receives a program in the data input unit 21. The microprocessor then signals the function selector 23 to decide on the type of weave, namely, knitting, weaving, or stitching depending upon the location. With the desired information there is a selection of needles by the needle selection unit 24. The operation is continuous by storing the process in the memory storage unit 22.
The product of the invention is made using chain stitches. The machine picks up the programmed material carrier and at the same time pre-selected needles raise up to knit the material. Then this material is dropped off and another material carrier is picked up which then knits this material in a pre-selected location. Using this process one is able to put material in any location in the product.
The present invention in its broadest aspect is a flexible unilayer textile performance fabric comprising a base fabric formed from a first fiber having the design of a desired pattern formed therein by intertwining or interlocking in the same layer at least one insertion fiber of a heavier denier than the base fiber which can be manipulated in accordance with conventional textile fabric manufacturing process but wherein such manipulation is computer controlled. A programmed computer encodes the location(s) and the design of the desired pattern. After such data is entered, this enables the manipulation processes to place such designs in designated locations. This effectively maximizes the benefits of the expensive high performance material while reducing the amount of material needed. For example, if abrasion resistance is needed in an anti-wear garment only those areas requiring this added performance, i.e., elbows and knees would have the performance filaments to provide the desired characteristics.
Broadly, a method of manufacture of the unilayer flexible performance textile fiber comprises the steps of:
(a) manipulating a first fiber in a conventional manner to form a base textile fabric in a single layer; and
(b) manipulating at least one insertion of a fiber having a greater denier into the base textile fabric wherein this step of manipulating is computer controlled to produce a predetermined design for a pattern at a pre-selected location within the base textile fabric to form a performance fabric having enhanced performance function.
The first manipulative step involves a stitching operation which is performed by a knitting, sewing, or weaving machine to form a base textile fabric having a mesh or web configuration. The base is then downloaded into a knitting machine. The base textile fabric can comprise fibers, for example of a denier of about 15 to 1800.
The type of stitching in the first manipulative step may vary widely. Stitching and sewing methods such as chain stitching, lock stitching, and the like are illustrative of the type of stitching used for use in this invention. The nature of the stitching fiber or thread will also vary widely and any type of fiber can be used depending on the garment and its use.
More specifically, in a further step the manipulation of the dissimilar denier fiber into the base textile fabric is conducted on a programmed knitting machine. The programming means comprises a microprocessor connected electronically to a programming matrix that controls a fiber carrier while simultaneously activating a needle selection means responsive to an output signal from the microprocessor and then to a pre-selected needle which knits the insertion fiber into the web of the base fabric. This fiber carrier is released and in response sends a corresponding impulse to the microprocessor consistent with the input of the pattern and location data; another fiber carrier carrying another insertion fiber supplies the fiber to the pre-selected needle which knits the filament into the proper location in the web of the base fabric. The fibers can have a denier up to 6000.
The invented fabric can be produced on essentially conventional computer controlled textile fiber manufacturing equipment to produce such textile mechanical manipulative functions of sewing, knitting or weaving that are capable of producing the interlocking or intertwining steps of at least one dissimilar performance fibers into the base fabric and where this equipment is modified to effect the computer controlled processes described.
Several advantages flow from this arrangement. The design of the pattern and the textile mechanical manipulation step or steps may be placed into coding matrix electrically connected to the microprocessor unit. This input data may be stored as electrical data on any desired medium, such as a disc or tape. Once this data has been entered, the manipulative steps, i.e., knitting, can take place normally without any necessity to stop the machine or in general terms where to locate the design on the base fabric and where the pattern should begin and end. Units of pattern information so stored are read in sequential order of knitting and are translated into pattern data for needle selection in each knitting course and/or control data for controlling knitting, transfer, rocking and like operations in each knitting course.
The following definitions are supplied in order to more clearly point out the present invention and to avoid ambiguity.
The term “fiber” is meant any thread, filament, or the like, alone or in groups of multifilaments, continuous running lengths or short lengths such as staple. Fiber is defined as an elongated body, the length dimensions of which is much greater than the dimensions of width and thickness. Accordingly, the term fiber, as used herein includes a monofilament elongated body, a multifilamented elongated body, and the like having regular or irregular cross sections. The term fibers includes a plurality of any one or a combination of the above.
The cross-section of fibers for use in this invention may vary widely. Useful fibers may have a circular cross-section, oblong cross-section or irregular or regular multi-lobal cross-section having one or more regular or irregular lobes projecting from the linear or longitudinal axis of the fibers. In the particularly preferred embodiments of the invention, the fibers are of substantially circular or oblong cross-section and in the most preferred embodiment are of circular or substantially circular cross-section.
The term “filament” as used herein refers to a strand of indefinite or extreme length. This term includes manufactured strand produced by extrusion processes, inter alia.
In this disclosure the terms “fiber”, “filament”, and “yarn” are used interchangeably. The term “yarn” is meant any continuous running length of fibers or filaments which may be wrapped with similar or dissimilar fibers, suitable for further processing into fabric by braiding, weaving, fusion bonding, tufting, knitting, or the like, having a denier less than 10,000.
The term “strand” is meant either a running length of multifilament end or a monofilament end of continuous fiber or spun staple fibers, preferably untwisted having a denier of less than 2,000. The term “insertion fiber” is meant any fiber or filament or yarn of a heavier denier than the base fiber. The insertion fiber may be of the same or different material than the base fiber. The type of fibers used in the fabrication of the present unilayer include natural and synthetic polymer fibers and inorganic filaments.
The term “denier” is a unit of weight indicating the finesse of the fiber, filament, or yarn equal to a yarn weighing one gram per each 9000 meters.
The term “overall denier” refers to the denier of a single strand on the combined denier of two or more strands. Again other overall denier sizes may be used depending on a number of factors to include but not limited to the knitting equipment that will be employed and to the end use of the knit article.
The strands for both the base fiber and the insert fiber may be comprised of any suitable natural or synthetic material suitable for use in a knitting operation. Suitable materials include nylon, polyester, polyester-cotton blends, cotton, wool, and acrylic fibers. The strands may be either spun or textured. The denier of the additional strands will vary depending on the equipment available and the desired final size of the composite yarn.
The heavier denier fabrics can be of equal or different denier and each has a denier within the range of about 500 to about 6,000 and preferably within the range of about 1,000 to about 5,200. The lighter denier yarns which make up the base fabric can also be equal or different and each has a denier within the range of about 220 to about 1,800.
Individual fibers or filaments may have a denier of about 50 and about 300. More preferably, the fibers may have a denier of between about 175 to about 250. The “insertion fiber” can be any fiber or yarn of a heavier denier than the base fabric which may be inclusive of a fiber or filament having modular of elasticity of about 5,000 kg/mm2 or more that provides an enhanced performance function, such as in cut resistance, abrasion resistance, heat resistance, or the like.
In general the specific filament or fiber combination which is employed in any particular situation will depend to a large intent to the functional use of the apparel or article. In the present invention along with enhancing the performance characteristics of the garment or article, the single layer construction reduces the weight and increases the flexibility and comfort factor. Furthermore, since the insertion fiber can be specifically located anywhere on the fabric and when the insertion is a high performance fiber the amount along with the expense can be reduced in the manufacture of a garment without the performance feature being diminished.
Preferably the filaments having a high tensile modulus of elasticity of 5,000 kg/mm2 or more are usable for the performance fibers which are knitted into the base fabric with the proviso that the denier is heavier. Illustrative of the useful organic fibers having a high tensile modulus are those selected from the group consisting of aramid fibers, liquid crystal, copolyester fibers, nylon fibers, polyacrylonitrile fibers, polyester fibers, high molecular weight polyvinylalcohol fibers and ultra high molecular weight polyolefin fibers and mixtures thereof.
High molecular weight polyethylene and polypropylene fibers are polyolefin fibers that may be used as performance fibers in preferred embodiments. In the use of polyethylene, suitable fibers are those which have a molecular weight of at least 150,000, preferably at least one million, and more preferably between two and five million. Such extended-chain polyethylene (EC PE) fibers are a high tensile material which are inherently resistant, as well as, being abrasion resistant and flexible providing a superior cut resistant yarn especially for protective gloves. SPECTRA® is a tradename of an ultra high molecular weight extended-chain polyethylene that is marketed.
Similarly, high oriented polypropylene fibers of molecular weight at least of 20,000 preferably at least two million, and more preferably at least two million may be used. Such high molecular weight polypropylene may be formed into reasonably well oriented fibers by techniques prescribed in U.S. Pat. No. 4,551,293 which is herein incorporated by reference. The particularly preferred ranges for the above-described parameters can advantageously provide improved performance in the final article and employed as a performance fiber.
High molecular weight polyvinyl alcohol fibers having a high tensile are described in U.S. Pat. No. 4,440,711 which is herein incorporated by reference. In the case of polyvinyl alcohol (PV-OH), PV-OH fibers having a weight average molecular weight of at least 200,000 may be used. Particularly useful PV-OH fibers should have a tensile modulus of at least 5,000 kg/mm2 or more. Most preferred fibers are poly-p-phenylene terephthalate filaments marketed under the tradename KEVLAR® and poly-m-phenylene terphthlate marketed under the tradename NOMEX® each by E. I. DuPont de Nemours & Co., Inc., Wilmington, Del. Each such aramid fiber has strong high temperature resistant, cut resistant, puncture, and abrasion resistant properties. Most preferred are para-aramide fibers having a high tensile modulus of elasticity of about 7,100 km/mm2.
Another high tensile fiber useful in certain applications of this invention is formed from polybenzimidazole polymers available from Celenese Corporation, Chatham, N.J., under the tradename P.B.I® fibers.
Polyacrylonitrite (PAN) fibers of a molecular weight of at least 400,000 are suitable. Such fibers are disclosed in U.S. Pat. No. 4,535,027, which is herein incorporated by reference.
Liquid crystal copolyesters suitable in this invention are disclosed in U.S. Pat. Nos. 3,975,487 4,118,372 and 4,161,470 all herein incorporated by reference.
In the case of nylon fibers, suitable fibers include those formed from nylon 6, nylon 10, and the like.
Suitable polyester fibers include polyethylene terephthalate.
Illustrative of useful inorganic fibers having high tensile modulus are those selected from the group consisting of S-glass fibers, E-glass fibers, steel filaments, carbon fibers, boron fibers, aluminum fibers, zirconic-silica fibers, aluminum-silica fibers, and mixtures thereof. Preferred are glass fibers having a tensile modulus of elasticity of about 7,000 kg/mm2. Preferred steel filaments have a tensile modulus of elasticity of about 20,000 kg/mm2.
Low tensile modulus fibers having a tensile modulus of 3,000 kg/mm2 or less are effective for importing the high degree of flexibility to the unilayer base fabric and the subsequent garment manufactured therefrom.
The synthetic fibers are preferably selected from the group consisting of vicose rayon fibers, aliphatic polyamide fibers, polyacrylic fibers, polyester fibers, water insoluble modified polyvinyl alcohol fibers and mixtures thereof. Most preferred fibers for the base fabric are natural fibers such as cotton and wool. Both fibers have the flexibility characteristics desired and provide a proper comfort level to the wearer. For these reasons they can be positioned proximate to the wearers skin.
Fibers having a relatively low tensile modulus can be used independently or together with ordinary relatively low tensile modulus fibers, without difficulty, in the method of this fiber.
The performance fiber can also be a blend of mixed fibers, i.e. a lower strength fiber with the high stretch fiber. Likewise, the performance fiber could be a composite fiber wherein the matrix is a softer material impregnated with a hard material such as carbon or glass fibers.
In addition, the fibers can be composed of fibers with anti-microbial additives or otherwise impregnated with an anti-microbial agent.
Even one skilled in the art might assume that the hard fibrous materials used as part of this invention would be very brittle and therefore of limited use in protective garments where flexibility and comfort are of major concern. The glass or steel filaments which are normally used as performance fibers are extremely small in diameter but could still be larger than the base fabric. If a larger diameter is required, an impregnated fiber, described above, can be used. As a result, these hard materials are still very flexible and can be bent round a very small radius without breaking. In this embodiment it is preferred that the hard fibrous material is located within the matrix of the yarn. By placing the hard material in the matrix of the yarn, the hard material is exposed to the least stress during the bending of the yarn. Furthermore, by placing the hard material within the matrix, the outer portion of flexible material helps to protect the more brittle, harder component.
In many cases, it will be preferred that the hard fibrous material be coated with a continuous layer of elastic material. This coating has several functions. For example, if the hard material is a multifilament fiber, the coating holds the fiber bundle together and helps prevent it from stresses that develop during the manufacturing process. Furthermore, the coating may provide a physical or chemical barrier for the hard material. Finally if the hard material is broken during use, the coating will trap the material so that it will not leave the fibrous structure.
It is to be understood that the present invention provides for a multiplicity of embodiments by using any of a large number of protective materials in combination to form a composite in a single layered fabric. Consequently, the invented fabric can be made into a large variety of articles and protective apparel used for protection against numerous potential hazards.
A glove having isolated patterns of high denier fibers in critical locations is prepared.
The method of manufacture involves first chain-stitching a 100 percent cotton 500 denier fiber on a programmed flat knitting machine, such as described in U.S. Pat. No. 4,479,368 to form a base fabric in a mesh and web construction having a weight of about 4 to 7 oz/sq yd. After the base fabric is formed it is downloaded into a knitting machine into which the design of the isolated patterns have been programmed. A cotton fiber having a denier of the individual filament of 1500 is knitted into the same layer as the mesh and web of the basic fabric. The movement of the knitting needle with respect to the palm portion and the finger and thumb stalls is controlled by a computer.
To complete the assembly of the glove, the edges of the back and palm portions, along with the finger and thumb stalls are secured by sewing in suitable fibers.
The glove has the desired qualities of high gripability, flexibility, and softness.
It should be apparent to those skilled in the art, that other embodiments, improvements, details and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims construed in accordance with patent statutes, including the doctrine of equivalents.